Automatic relief-valve for tires.



v. 0. JARVIS. AUTOMATIC RELIEF VALVE FOR TIRES. APPLIOATION FILED TUNE9., 1913.

1, 1 04,902. Patented July 23, 191

VIBG-IL O. IL LRVIS, 0F HANFORD, CALIFORNIA.

AUTOMATIC BELIEF-VALVE FQR TIRES.

Specification of Letters Patent.

Patented July 28, 1914;.

Application filed June 9,1918. Serial No. 772,497.

To all whom it may concern Be it known that I, VIRGIL 0. JARVIS, a

citizen of the United States, residin at Hanford, in the countytof Kingsand tate of California, have invented a new and useful AutomaticRelief-Valve for Tires, of which the followin is a specification. Thisinvention re ates to an automatic relief valve for tires, and has forits object to provide a device which may be screwed to the outer end ofa tire valve stem, and which will operate to automatically relieve thepressure in the tire when the pressure in the tire increases to acertain point.

A further object is to so construct the devicethat it may be adjusted tocause the pressure to be released at the desired point.

A further object of the invention is to so construct the device that itwill be contained vwithin the usual dust cap on' the valve stem.Referring to the drawings: Figure 1 is an enlarged longitudinal sectionthrough the upper portion of a tire valve'stem showing the device inposition thereon. Fig. 2 1s a section online m -m ,'Fig. 1. Fig. 3 is asection on line w w Fig. 1. Fig. 4 is a sectional view of the lowerportion of the device, showin the valve inverted with a ball interposebetween the valve and its seat.

1 designates the body of the tire valve stem havin a reduced threadedend 2. 3 designates t e valve pin, all of which are of the usualconstruction.

4 is a barrel with an enlarged lower internally threaded socket 5, whichis adapted to be screwed on the reduced end 2. the socket 5 is a rubbergasket 6, whichseats against the upper rim of the reduced end 2 andprevents air leakage.

7 is a plate with a cupped center ortion 8, which is adapted to depressthe va ve pin 3 to permit the air to pass from the tire into theautomatic pressure relief valve. The cupped portion 8 has severalperforations 9 for the air to pass therethrough.

The barrel 4 is internally threaded at 10 and screwed therein is asleeve 11 with a thumb piece 12 for turning it and having several airescaping orifices 13. A coil compression spring 14 is arranged withinthe barrel 4, and one end bears against thumb piece 12, and the otherend bears against the cod of a valve pin 15, there being a rubberpacking 16 under the valve head 15, which Within seats against anabutment or seat 17 formed inside the shell 4. The valve head 15 isformed with a central conical, portion 18, and the abutment 17 is formedwith a central conical ortion 19. If the rubber gasket becomes 0st, thevalve may be inverted as shOWn in Fig. 4, and a ball 19 inserted betweenthe valve head 15 and abutment 17, the ball being held centrally by theconical portion 18 in valve head 15, and by conical portion 19 inabutment 17.

In operation the pressure of spring 14: holds the valve 15 with rubberwasher 16 against abutment 17 with sufficient pressure to maintain theair within the tire until the pressure of the air has increased tosuchan extent that it overcomes the pressure of spring 14, whereupon thepressure of air opens valve 15, and allows vair to escape from the tire,the air after passing valve 15 escaping through the perforations 13. Byregulatlng the thumb piece 12 any desired pressure of spring 14; may be.secured to cause the valve to automatically open at thedesired definitepressure.

As the device is screwed to the reduced end of the valve stem 2 itpermits the usual dust cap not shown to be applied to the valve stem sothat the automatic relief valve is housed and protected from injury.

What I claim is An automatic relief valve for tires, comprising a shellhaving an internally threaded socket adapted to be screwed on the end ofthe tire valve stem, means in said socket for depressing the valve pinof the tire valve, and said shell havin an abutment, and areversiblevalve provid ed on one of its faces with a rubber seat for engagementwith said abutment when the valve is in one po sition, and having aconical recess in its opposite face to receive a ball resting againstsaid abutment when the position of the valve is reversed, a sleevescrewed into said shell, a compression spring within the shell betweenthe valve and sleeve, the sleeve havin a thumb piece on the end thereoffor ad justment.

In testimony whereof, I have hereunto set my hand-at Hanford Cal. this2nd day of June 1913.

' VIRGIL 0. JARVIS.

In presence of- GEO. E. WORTHINGTON, ED. T. SMITH.

